BBS02 battery no led indicator when connected to bike

[Lyss]

Hello! I am experiencing an issue with my relatively new BBS02 which I installed the summer of 2023.

One morning my BBS02 suddenly did not turn on. The battery LED indicators are not working when connected to the battery, but do light up normally when disconnected. When I connect the battery to the motor, there seems to be some kind of short circuit where the motor tries to 'pedal' (the pedals move slightly forward) for one millisecond.

After that the motor display does not light up, no effect from the motor, and no battery LED indicators.

I've tried rewiring the battery connectors to the motor, but that didnt help at all. Does anyone here have any suggestions on how to start debugging this, or theories for what causes this?

 

[docw009]

Sounds like a bad short circuit fault inside the BBS02 controller. The battery BMS detected a high current fault and shut off the battery. That turns off the LED. When you remove the short circuit by disconnecting the battery, it will reset after a few moments and the LED works again,

Did someone attach a new connector and wire it backwards?

I seem to remember doing that with a BBS02 install a year ago, I flipped the darn XT60 around, No ill effects, because the BMS shut down the battery immediately, Otherwise, I don't see how this happens on a working installation, unless a cable worked loose inside the notor and short circuited,

 

[Lyss]

Sounds like a bad short circuit fault inside the BBS02 controller. The battery BMS detected a high current fault and shut off the battery. That turns off the LED. When you remove the short circuit by disconnecting the battery, it will reset after a few moments and the LED works again,

Did someone attach a new connector and wire it backwards?

I seem to remember doing that with a BBS02 install a year ago, I flipped the darn XT60 around, No ill effects, because the BMS shut down the battery immediately, Otherwise, I don't see how this happens on a working installation, unless a cable worked loose inside the notor and short circuited,

I did re-solder the connectors the day before this error happened, so that seems logical. I was able to ride to work for 2 days before it stopped working again, so I didnt realise this could have been an issue.

When you say "wire it backwards", do you mean which side the male/female connectors are soldered to, or polarity? I guess I wouldnt have been able to ride at all if the polarity was not correctly wired.

 

[docw009]

Yes. Backwards. I soldered the XT connector to the battery cradle just after mounting the cradle on the bike. Was not paying attention and ZAP.

 

[Lyss]

Yes. Backwards. I soldered the XT connector to the battery cradle just after mounting the cradle on the bike. Was not paying attention and ZAP.

The connectors are wired correctly, so I dont think that the issue. But maybe the connectors themselves or the cables from the motor have taken damage which causes short circuiting...